Automatic ciectjit changek



May e 1924. 1,493,026

- D. A. DICKEY AUTOMATI C lCIRCUIT CHANGER Filed Aug. '7, 1923K 2 Sheets-Sheet 1 TTORN: Y

May 6 1924.

1,493,026 D: A. DICKEY l AUTOMATIC CIRCUIT CHANGER Filed Aug. 7` 1925' 2 Sheets-Sheet 2 INVENTOR UH/WEL /C/ff BY latented May 6, 1924.

PATENT OFFICE.

DANIEL ADAM DICKEY, OF DAYTON, OHIO.

AUTOMATIC CIRCUIT CHANGER.

Application filed August 7, 1923.

To all eli/tom t may concern:

Be it known that I, DANIEL ADAM DICK- EY, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Automatic Circuit Changers, of which the following is a specification.

This invention relates to an automatic circuit interrupter for limiting the speed of an engine by automatically breaking or grounding the electrical ignition circuit.

There are many cases where as a matter of safety, it is necessary to employ a device which will limit the speed of an engine, and an instance of such a case is in the reversible propeller. lVhere such reversible propellers are used in aircraft, there is a period when the angularity of the blades is passing through a neutral position, that the load is almost entirely removed from the engine which would cause a very disastrous result, due to the high speed the engine would obtain unless such an automatic cutout is used.

The primary object of this invention is to provide a. device of this character which will function quickly and positivelyat some predetermined speed. A further object is to provide means in such va device to maintain the condition of suspended operation until the speed has fallen to a predetermined lower limit. Other objects will be more fully set forth in the attached specification and claims and in the drawings, in which:

Fig. 1 is a perspective view of the circuit interrupter,

Fig. 2 is a perspective view of the rotating parts of the circuit interrupter removed from their supporting cases.

Fig. 3 is a detail view of the circuit closing device,

Fig. 4l is a detail of the supporting block.

Fig'. 5 is a view of one of the weighted governing members,

Fig. 6 is a plan view of the spring plate stop member, and

Fig. 7 is an end elevation of the governe ing mechanism showing the support-ing members in section.

Referring to the drawings by reference characters', the numeral 1 designates a metallic housing in which the governing rotat- Serial No. 656,278.

ing parts are contained. Attached to the end wall 2, of the casing is a disk 3, provided with a rearward extending bearing member 1, which rotatably supports the shaft 5 upon which is mounted the rotating parts of the device. It will be understood that the circular outer track of the casing is suitably insulated from the disk' and the rotating parts of the device. Mounted upon the shaft 5 so as to rotate therewith, is a support-ing member 6, beneath which is a comparatively7 thin sheet of metal 7, the parts 6 and 'T being held t-o the shaft 5 by means of a threaded extension of the shaft and nut S thereon. rThe supporting member 6 is provided with al threaded hole 9, near one end thereof, and a second threaded hole 10, is provided near the opposite end of the member. These. holes 9 and 10 support the studs 11 and 12 respectively, which are threaded into these holes and these studs support the governing members 13 and 14.- respectively.

llach governing member 13 and 14 is provided with a weight 15, and each is provided with a projection 16 'and a side ear or projection 17, each ear 17 supporting a stud 18. These two governing members are connected by an equalizer consisting of links 19 and 20 which are vconnected to theI mein bers 13 and 14 respectively, and these links are interconnected by a central link 21 which is pivoted centrally and is freely rotatable on the upper extension of the shaft 5. This equalizer serves to maintain the weighted ends 15 of the two governing members at equal distances from the center of rotation. Between the weighted member 14 and the supporting member G is a contact carrying device 22, which is shaped genera-ll in the form of a disk and which is provided with a center hole 23 through which the stud 12 extends, thus permitting free rotational movements of disk 22 thereon. The disk is provided with a pin 24 and a notch 25 is provided along its outer edge. A contact member 26 formed of spring metal is attached by means of a screw' 27 to the outer circumference of the disk 22. A similar contact carrying device is provided between the governing member 13 and the supporting bar 6. The two pins 24. of the Contact carrying devices are urged by spring means i' direction (see Fig. 1), so as to interrupt the circuit, which is completed through the contact members 26 and the metallic casing 1, it being understood that the track of the casing 1 is electrically connected to one wire and the rotating governing parts are electrically connected to a second Wire, these wires leading to the ignition circuit or to the throttle control mechanism so that when this circuit is completed the motor will be slowed down or stopped. It is preferred to have the casing 1 connected to the live ignition wire and the rotating governing means connected to the ground, so that the ignition may be grounded when the contact members 26 touch the casing 1.

rIhe governing arms 13 and 14 and the disks 22 are interconnected through the studs 18 and pins 24 by means of springs 28 and 29, these springs serving to urge the governing-members and disks in a clockwise direction, seeFig. 1, which is the normal position maintained by these members when the device is stationary or rotating at lowspeeds. .The-stud 18 of one governing member is connected to pin 24 of the opposite disk so that the springs 28 and 29 are positioned parallel. The pins 24 of the circuit closing devices are so positioned that they will each be in a notch 30 of the governing members, and the circuit closing devices arev urged by thesprings so that the pins 24 are maintained in the notches 30 of the governing members, unless they are otherwise prevented in a manner which will now-'be more fully set forth.

The latching member 7 which is constructedof a bottom metallic sheet 31 and side sheetsor extensions 32 and 33, is provided with anfupwardly extendinglatch 36, which extends within a notch 34 of the supporting member 6 and which is of sutlicient length so that it projects above the top of the member 6, as shown in Fig. 2, and projects into the notch 25 of the circuit closing device and maintains this circuit closing device in the position shown in Figs. 1 and 2, unless released. It will be unders'toodthat av similar latch is provided at the opposite endet the member 7 so as to lock the other circuit closing device in a similar manner. The member 7 is attached to the shaft 5 by means ofthe center hole 37, so as to rotate therewith. At the center of the 'member 7 the parts 6 and 7 are held together vby the pressure exerted by the nut 8, but at points'remote from the center of the member 7 this member is entirely disconnected from the parts 5, 13 or 14, and it is constructed of material having suilicient' springiness so that when a downward pressure is-exerted on the ends 32 and 33, the outer ends of the member 7 are moved downwardly in relation to the ends of the member 6, and the latches 36 are withdrawn from the notches 25 of the circuit closing device.

The governing member 14 is provided with a rearward extension 16, so that this extension when moving horizontally about the stud 12 may operate upon a curved cam face. 35 more fully shown in Fig. 7, and press downwardly upon this cam face so as to release the latches 36, after the governing member 14 has been moved a considerable distance in clockwise direction from the position shown in Fig. 1 to the position shown in Fig. 7. Vhen the latches 36 are released in this manner, the springs act upon the circuit closing devices and move the contact strips 26 so as to interrupt the contact between these strips and the casing 1.

When the engine is ruiming at normal speeds, the weights 15 are spinning-in their iii-position so that these weights are close to the center of rotation. This is the position shown in Fig. 7.y The contact members 26 are at this time also in their inposition and the ends are considerably removed from the casing.` 1. lVhen the speed reaches the predetermined limit tor which the cutout is set,.the weights start to fly out due to centrifugal force acting against the tension of the springs 28 and 29. The spring restoring moment may be made adjustable so as to vary the speeds at which the device operates by adjusting the spring tension or the position of the pins 24 or studs 18. After the weights have been moved out :tor a short distance, the centrifugal force greatly' increases, due to the greater distance between the weights and the center of rotation. The spring tension also increases, due to the increased distance between the studs 18 and pins 24, but it will be seen lthat the moment arm of the spring force has, at the same time decreased. The increase in the pull of the spring and the decrease of the moment arm are so arranged that the effective spring restoring force on the members 13 and 14 increasesslightly'as the weights move out. The increase of the spring restoring moment is comparatively small as compared with the increase ofcentrifugal force on the weights, as the latter move out, so that the weights will'fiy out with increasing speed until they reach the position shown in Fig. 1. As they do so, they carry with them the disks 22 and contact strips 26, due to the location of the pins 24 of these disks in the grooves 30 of governing members, so that these circuit closing devices are positively operated by the governing members. The contact will be made between the strips 26 and the casing 1 so as to cause a decrease in the speed of the engine byl grounding the ignition. As

CJI

lthe governing arms 13 and `14 Imove outwardly, the rearward extension 16 is moved away from the cam face 35 and the Vlatches 36 are permitted to move upwardly and engage the notch 25 of the'circuit closingdevice as soon as the circuit closing disk 22 has reached its outer position as shown in F ig. 1, with the governing weights 15 in their outermost position as just described. The spring contacts 26 are under sufficient tension when in their outer position so that any bounding or breaking of the circuit is prevented.

Vhen the speed falls a slight amount, the governing members 13 and 14 will not be moved, since the centrifugal force on the members 15 in their outer position is considerably more than the force which originally started them in their outward movements. After the speed falls to a sufficiently low predetermined value, the centrifugal force on the weights is decreased considerably so that the spring tension of the spring 29 returns the weights 15 and the arms 13 and 14 to their normal or inner position, this returning movement taking place with increasing rapidity as the weights approach their inner positions, due to the rate of decrease of the centrifugal force.

The motion of the weights 15 does not affect the disks 22 of the circuit closing devices when these weights are moving from their outermost position to a position closely adjacent to their inner position, since the latches 36 on the latch plate project into the notches 25 and hold these disks 22 in the position shown in Figs. 1 and 2. These disks are maintained in this position until the governing arms 13 and 14 have nearly reached their inner position. At this time the projections 16 act upon the cam face 35 and release these latches S6 so as to permit the springs 28, 29 to quickly return these circuit closing devices to their normal position. .Tt will be understood that the weights aie moving with a considerable speed inwardly at the time they start to release the locking latches; the contacts will be broken practically instantaneously by the swift inward movements of the spring cont-act members 26. Any tendency of the governing weights to move inwardly a slight amount and then move outwardly again, due to fluctuations of speed when the weights are in their outermost positions, will have no tendency to in any way affect the circuit as the circuitis positively maintained until the speed of the engine has decreased a considerable amount and permitted the weights to be moved to their normal inner positions.

I claim:

1. An automatic circuit changer comprising a mounting and a governing means rotatably suppoited thereon, to rotate about an axis and comprising a weighted member supported so as to rotate about said axis, a ydevice operated in one direction by said member, yielding lmeans Aurging said member to normal position and means for maintaining said device in a predetermined.posiforth in claim 1, together with means operated by said weighted member for releasing said maintaining levers.

4. Au automatic circuit changer as set forth in claim 1, together with yielding means for returning said device to a normal position.

5. An automatic circuit changer as set forth in claim 1, together with yielding means for returning said device to a normal position and means for releasing said maintaining means to allow said yielding means to quickly return said device to its normal position.

6. An automatic circuit changer comprising a mounting and a governing means rotatably supported thereon to rotate about an axis, said governing means comprising a supporting member, a plurality of weighted members pivoted on said supporting member at points remote from said axis, a pluralitv of devices operated positively by said vweighted members, yielding means interconnecting said devices and said weighted members, means for maintaining said devices in predetermined positions after their operation by said weighted members and means operated by said weighted members for releasing said maintaining means, said devices serving to complete an electrical circuit when in their said predetermined positions.

7. An automatic circuit changer comprising a mounting. a centrifugal governing weight supported thereby to rotate about an axis. yielding means for said governing weight to act against the centrifugal force on the member, and means connecting said yielding means to said governing weight so that as the governing weight moves outwardly away from said axis, the spring returning moment increases, the rate of increase of the spring returning moment being slower than that of the centrifugal force.

8. An automatic circuit changer as set forth in claim 1. said yielding means being connected to said weighted member so that as the governing weight moves outwardly away from said axis, the spring returning moment increases, the rate of increase of the spring returning moment being slower than that of the centrifugal force.

9. An automatic circuit changer as set forth in claim 1, said yielding means connected to a point on said Weighted members whichy moves as said Weighted member moves so asto decrease the moment arm of said spring force as the Weighted member 10 moves outwardly due vto centrifugal force. In testimony whereof I affix my signature.

DANIEL ADAM DICKEY. 

